| The level of pea leaf weevil feeding damage was the lowest observed in the past eight years. The highest damage ratings were along Highway 2 and southern Alberta with reduction in adult damage by pea leaf weevil in eastern Alberta. Pea leaf weevil is now established from southern Alberta through west-central Alberta as far as Barrhead County northwest of Edmonton. The survey also shows that pea leaf weevil is now found in several counties in the Peace River region. Feeding damage in the spring of 2018 remains low in the Peace but reports of high numbers of adults in August may indicate a change to that situation.
While this is not a strict forecast, experience has shown us that activity levels greater than 9 notches per plant is sufficient to cause significant damage if conditions are favorable in the spring of 2019. This covers a large area of southern and west central Alberta. For any producers south of Highway 9 and along Highway 2 up to Edmonton there is a risk of damaging levels of pea leaf weevil in 2019. Producers should use this information along with their own experience to plan control strategies such as seed treatment for the 2019 crop year. Research has shown that seed treatment is much more effective in reducing losses from pea leaf weevil than foliar treatments.
In addition, since 2014 significant pea leaf weevil damage has been seen on fababeans in a much larger area than shown in this survey that is conducted on field peas. This insect causes as much or more damage on fababeans. The true economic damage of this insect on both peas and fababeans on the higher organic matter soils of central Alberta is not well understood but research has been initiated to work out these relationships.
Spring weather conditions have a very large impact on the timing and severity of pea leaf weevil damage. When warm conditions (>20 C) persist for more than a few days in late April or early May the weevils arrive in fields early. Early arrival corresponds to the potential for higher yield losses. In years where cool weather persists, the arrival of PLW can be much later and the resulting yield impact is lower especially when the crop advances past the 6 node stage before weevils arrive. In every case control decisions should be made on a field by field basis.
Spring weather conditions have a very large impact on the timing and severity of pea leaf weevil damage. When warm conditions (>20 C) persist for more than a few days in late April or early May the weevils arrive in fields early. Early arrival corresponds to the potential for higher yield losses. In years where cool weather persists, the arrival of PLW can be much later and the resulting yield impact appears to be lower especially when the crop advances past the 6 node stage before weevils arrive. In every case control decisions should be made on a field by field basis.
Life cycle information
Frequently Asked Questions
Historical pea leaf weevil survey maps from 2008-2017. |